return the two biggest numbers in a list of dictionaries

def get_two_biggest_numbers(a_list):
    biggest_number = a_list[0]['number']
    second_biggest_number = a_list[0]['number']
    for element in a_list:
        if element['number'] > biggest_number:
            biggest_number = element['number']
        elif element['number'] > second_biggest_number:
            second_biggest_number = element['number']
    return biggest_number, second_biggest_number